Mordant-dyeing monoazo dye and its production



UNITED STATES PATENT OFFICE MORDANT-DYEING MONOAZO DYE AND ITS PRODUCTION Max Raeck, Dessau in Anhalt, Germany, assignor to General Aniline Works, Inc., New York, N. Y., a corporation of Delaware No Drawing. Application October 5, 1935, Serial No. 43,782. In Germany December 18, 1934 2 Claims. (01. 260-91) My present invention relates to a process for added to an ice-cold magna, made by stirring manufacturing a new monoazo dye and to the with water a paste of 16 kilos of 1,5-dihydroxydye obtainable according to this process. naphthalene. Caustic soda lye is then added In German Patent No. 157,786 there are deuntil the reaction is feebly alkaline, whereupon 5 scribed mordant-dyeing monoazo dyes, made by coupling occurs and is rapidly at an end; the ex- 5 coupling an ortho-aminophenol sulfonic acid or a cess of caustic soda lye is neutralized with hydrosubstitution product thereof with 1,5-dihydroxychloric acid, the dye is filter-pressed and dried.

naphthalene. It dyes wool in an acid bath dull violet-red. This invention consists in the manufacture of When after-chromed the shade becomes a full a dye by coupling the hitherto unknown diazobloomy black, 10

tized 3,4,6-trichloro-2-amino-l-hydroxybenzene- What I laim is:

5-sulfonic acid with 1.5-dihydroxynaphthalene. 1. The process which comprises di t This dy y 011 W001 and after-Chromed, yields ing 3,4,6 trichloro-Z-amino-l-hydroxybenzenea b k Which, as Compared With the hitherto 5-su1f0nic acid and coupling the diazo compound known black, is characterized by a very fine shade with l5 dihydroxynaphthalene 15 and much improved fasteness to light as well as The dye which corresponds to the formula having good general properties of fastness.

Diazotized 3,4,6-trichloro-2-amino-l-hydroxy- OH OH benzene-5-sulfonic acid may be obtained as foll O 1ows:3,4,6-trichloro- 2- amino 1 hydroxyben- 01- -N=N zene is converted, by means of phosgene, into the benzoxazolone. This is sulfonated, whereby the Naoas c1 sulfo group enters the vacant 5-position and the oxazole ring is saponified. The following example illustrates the inven- 25 tion: which dyes wool in an acid bath a dull violet-red 29.25 parts of 3,4,6-trichloro-2-amino-l-hyshade which when after-chromed, becomes a full droxybenzene-5-sulfonic acid are diazotized in bloomy black. 7 the usual manner and the diazo compound is MAX RAECK. 

